It was a news item.
This is how I heard of it more or less...
An older couple was on vacation, walking on a remote beach. He suffered a medical emergency, she called 911 and could not describe where they were.
The operator asked if she had the 3 word app and to give her the 3 words. She did and rescue was minutes away.
The app is to give others your location in a few simple clicks.
The kids get separated at Disney World. Within the app they send you a text. It gives the location on a google map, Click "direction" and it leads you there. Can even send a picture with the 3 words embedded on it.
Now you could do it all the long way with repeated instructions until the other person figures it out or you could do it in 2-3 clicks... easy-peazy
3 words